SwitchQNet: Optimizing Distributed Quantum Computing for Quantum Data Centers with Switch Networks.

Distributed Quantum Computing (DQC) provides a scalable architecture by interconnecting multiple quantum processor units (QPUs). Among various DQC implementations, quantum data centers (QDCs) - where QPUs in different racks are connected through reconfigurable optical switch networks - are becoming feasible in the near term. However, the latency of cross-rack communications and dynamic switch reconfigurations poses unique challenges to communications in QDCs, significantly increasing the overall latency, thereby also reducing the overall fidelity. In this paper, we address these challenges by introducing a novel compiler that optimizes scheduling of communications across the program and network layers. Our evaluation shows that it reduces the overall latency by 8.02x over prior approaches with a small overhead and can be integrated with quantum error correction (QEC) to facilitate fault-tolerant quantum computing (FTQC). We have open-sourced our codes at https://zenodo.org/records/15377656.